The present invention relates to a vacuum processing apparatus formed by connecting a plurality of processing units which process samples in processing chambers in vacuum containers to a plurality of vacuum transfer containers through depressurized insides of which substrate-shaped samples to be processed such as semiconductor wafers are transferred.
Among processes for manufacturing semiconductor devices, there are an etching process for processing a semiconductor wafer (hereafter referred to as a wafer) which is a substrate-shaped sample using a corrosive gas, a film forming process which needs processing at a high temperature, and an ashing process for conducting ashing processing on a mask used in the etching process and removing the mask. Among these processes, there are processes in which it is necessary to conduct a specific processing on a wafer processed using a corrosive gas at a high temperature (in the range of approximately 800° C. to 1,000° C.) after the processing.
This is because, if processing is conducted at the high temperature when conducting the ashing processing, for example, a wafer immediately after the processing remains at the high temperature, and there is a case where the wafer may be damaged due to an abrupt change in the temperature or products generated during the processing and particles of the processing gas remaining which stay around the high temperature wafer exert an unfavorable influence upon materials and members around the wafer when the wafer is transferred to the outside of the processing chamber as it is. In other words, if such a wafer immediately after the processing is transferred through the same transfer path as that before the processing, there is a possibility of causing a problem that an outgas is generated by a corrosive gas which adheres to the wafer or by excessive heating due to heat brought by the wafer and adheres to the wafer or contaminates a transfer robot or a transfer chamber.
Travel of a wafer after prescribed processing and before post-processing through the same transfer path as that of an unprocessed wafer in this way causes contamination of the unprocessed wafer, the transfer chamber which constitutes the transfer path, and members such as a robot therewithin.
Against such a problem, an example in which processing chambers can easily be added to or removed from the transfer chamber via gate valves and layouts of the processing chambers can be conducted respectively arbitrarily (see, for example, JP-A-6-349931), an example in which transfer capable of suppressing occurrence of cross-contamination is conducted by using a plurality of picks with distinction to hold processed wafers (see, for example, JP-A-2004-119635), and an example in which an intermediate path chamber which has a mounting stage and which can be evacuated to vacuum is provided between transfer chambers in a plurality of processing units and a gate valve in the intermediate path chamber is opened and closed properly to transfer without direct communication between the transfer chambers so that occurrence of metal contamination is suppressed (see, for example, JP-A-2000-150618) are known.